1. Field of the Invention
The present invention generally relates to devices for cutting sheet material such as sheet metal, vinyl or aluminum siding, and linoleum.
2. Description of the Prior Art
Various types of devices are presently used for cutting sheet material such as sheet metal, vinyl or aluminum siding, and linoleum. One type of device for this purpose typically has a pair of cooperating cutting wheels mounted in a housing so that both cutting wheels can rotate freely. The cutting wheels have sharpened, beveled cutting edges and are arranged in the housing such that the cutting edges are adjacent to and slightly overlap one another. In use, the edge of the material to be cut is positioned so that it will engage the cutting wheels at the point where the cutting edges overlap. Then, by pushing or pulling the cutting device across the material to be cut, or conversely, by pushing or pulling the material through the cutting device, the relative motion of the material and the cutting device causes the cutting wheels to rotate in opposite directions, cutting the material as it passes between them. Some cutting devices of this type are specifically designed to be used in combination with a sheet metal brake in order to make a straight cut through a piece of sheet metal clamped in the brake. In such an application, the cutting device is mounted on the sheet metal brake, which guides the cutting device to provide a straight cut.
One significant disadvantage of such prior art cutting devices is that they cannot be easily adjusted to vary the spacing between the cutting wheels. This can be a problem when attempting to cut materials having different thicknesses. For instance, when cutting heavier gauges of sheet metal, a cutting device having the cutting wheels immediately adjacent each other with no lateral gap between them will typically result in a bend in the cut edge, rather than a clean cut. In order to cut such heavier material without bending the cut edge, it is necessary to provide a slight lateral gap between the cutting edges of the cutting wheels. With known cutting devices, this adjustment requires partial disassembly of the cutting device in order to insert appropriate shims to achieve the desired gap. The necessary disassembly and reassembly can be very inconvenient and inefficient, especially when it is necessary to cut materials having different thicknesses.
Another disadvantage of the prior art cutting devices is that known devices intended for use in combination with a sheet metal brake are designed only for use with a particular type of sheet metal brake and cannot be used with brakes made by other manufacturers.
A further disadvantage of the prior art devices is that cutters intended for use in combination with a sheet metal brake are typically bulky and inconvenient to carry about, being intended for use while mounted on a sheet metal brake. Accordingly, they are typically poorly suited for use apart from a sheet metal brake, as might be necessary when cutting small work pieces at a worksite or making curved cuts.
Hence, there exists a need for a small, lightweight cutting device for sheet material that can be easily adjusted to provide a lateral gap of appropriate width between the cutting wheels in order to cut material of varying thickness without bending the cut edge and that can be used in combination with any sheet metal brake to make straight cuts or without a sheet metal brake for freehand straight or curved cuts.